/*
 * Copyright (c) 2020, 2022 Oracle and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.helidon.dbclient.metrics.jdbc;

import java.time.Duration;
import java.util.concurrent.Callable;

import org.eclipse.microprofile.metrics.Snapshot;
import org.eclipse.microprofile.metrics.Timer;

/**
 * {@link Timer} metric wrapper for Hikari CP metric.
 */
public class JdbcMetricsTimer implements Timer {

    private final com.codahale.metrics.Timer meter;
    private long elapsedTimeNanos;

    JdbcMetricsTimer(final com.codahale.metrics.Timer meter) {
        this.meter = meter;
    }

    @Override
    public <T> T time(Callable<T> event) throws Exception {
        long start = System.nanoTime();
        try {
            return meter.time(event);
        } finally {
            updateElapsedWithStart(start);
        }
    }

    @Override
    public void time(Runnable event) {
        long start = System.nanoTime();
        try {
            meter.time(event);
        } finally {
            updateElapsedWithStart(start);
        }
    }

    @Override
    public Context time() {
        return new JdbcMetricsTimerContext(meter.time(), this::updateElapsed);
    }

    @Override
    public long getCount() {
        return meter.getCount();
    }

    @Override
    public double getFifteenMinuteRate() {
        return meter.getFifteenMinuteRate();
    }

    @Override
    public double getFiveMinuteRate() {
        return meter.getFiveMinuteRate();
    }

    @Override
    public double getMeanRate() {
        return meter.getMeanRate();
    }

    @Override
    public double getOneMinuteRate() {
        return meter.getOneMinuteRate();
    }

    @Override
    public Snapshot getSnapshot() {
        return new JdbcMetricsSnapshot(meter.getSnapshot());
    }

    @Override
    public void update(Duration duration) {
        updateElapsed(duration.toNanos());
        meter.update(duration);
    }

    @Override
    public Duration getElapsedTime() {
        return Duration.ofNanos(elapsedTimeNanos);
    }

    private long updateElapsed(long delta) {
        elapsedTimeNanos += delta;
        return delta;
    }

    private long updateElapsedWithStart(long start) {
        return updateElapsed(System.nanoTime() - start);
    }
}
